Bug 2461147 (CVE-2026-41240) - CVE-2026-41240 DOMPurify: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization
Summary: CVE-2026-41240 DOMPurify: DOMPurify: Cross-Site Scripting (XSS) via inconsist...
Keywords:
Status: NEW
Alias: CVE-2026-41240
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2463430 2463432 2463429 2463431
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-23 16:05 UTC by OSIDB Bzimport
Modified: 2026-04-28 12:04 UTC (History)
98 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-04-23 16:05:05 UTC 
DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Versions prior to 3.4.0 have an inconsistency between FORBID_TAGS and FORBID_ATTR handling when function-based ADD_TAGS is used. Commit c361baa added an early exit for FORBID_ATTR at line 1214. The same fix was not applied to FORBID_TAGS. At line 1118-1123, when EXTRA_ELEMENT_HANDLING.tagCheck returns true, the short-circuit evaluation skips the FORBID_TAGS check entirely. This allows forbidden elements to survive sanitization with their attributes intact. Version 3.4.0 patches the issue.
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